In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date: publicly available, known to the public, part of common general knowledge or known to be relevant to an attempt to solve any problem with to which this specification is concerned.
Myriad types of eyewear have been used through the ages to improve eyesight or protect the eyes. For example, prescription lenses in the form of contact lenses or glasses are used to correct sight.
In industrial environments, eye protection is worn to protect the eyes from hazards including flying debris, air or gas jets, grit, sparks, acid splatters and strong energy sources such as welding arcs, lasers, and ultraviolet light. In medical environments, medical professionals such as surgeons and dentists wear protective eyewear to provide protection against entry into the eye of bodily fluids or other potentially infectious or damaging substances from a patient. Surgeons and dentists may also need to use magnification devices or other optical instruments whilst carrying out procedures on patients. Many sporting or leisure pursuits require eye protection. For example scuba divers require face masks to be able to see underwater, whilst skiers require tinted, wrap around glasses or goggles to protect their eyes from wind, particles of snow and UV radiation.
Conventional eyewear worn on the face is typically held in place by a nose piece and a pair of arms for locating the eyewear in known manner on the ears of the wearer.
While eyewear may have multiple functions, it is usually made for a specific purpose. For example, a scuba diver's face mask or skier's goggles may include prescription lenses, but can be used for no other purpose than scuba diving or skiing respectively.
Similarly, eyewear for use in industrial environments usually has no application outside the industrial environment.
This limited functionality of eyewear can be particularly inconvenient in certain applications. For example, a fly fisherman may stand at a river from dawn to dusk, in a wide range of light conditions, requiring several changes of eyewear to different polarizing lenses so that the fish may be seen in different light levels. Given the relatively high cost of a single pair of spectacles, it is not viable for a fisherman to have multiple pairs, each having a different set of polarizing lenses.
Apart from specialist applications such as fly fishing, many people wear spectacles and most have at least two pairs—a prescription pair and prescription sunglasses. They may also have a scuba diving mask with prescription lenses and/or skiing goggles with prescription sunglass lenses.
There is therefore a need for a modular eyewear system that allows the user to readily change eyewear elements, or the combination of eyewear elements according to their various activities and interests, thus dispensing with the need and expense of having multiple pairs of spectacles and other visual aids.